710 G. C. MARTIN TRIASSIC ROCKS OF ALASKA 



occurring in a synclinc and as underlain by volcanic rocks that were cor- 

 related with those of the Nicola series and which contain fossils that 

 Whiteaves doubtfully referred 65 to Pseudomonotis siibcircularis, possibly 

 also belong at this horizon. They should, however, not be confused with 

 the Middle Triassic beds (see page 705) of Thompson Eiver and of Mcola 

 Lake (?) with which Dawson correlated 66 them. 



Beds containing Pseudomonotis siibcircularis occur in a more or less 

 continuous belt along the eastern front of the Eocky Mountains of British 

 Columbia and Yukon. The known localities are on upper Pine Eiver; 07 

 on Peace Eiver, about 27 miles below the juncture of Pinlay and Parsnip 

 rivers, where the rocks have been described by Selwyn 6S and by McCon- 

 nell 60 as consisting of calcareous shales and impure limestones; and near 

 the headwaters of Stewart Eiver, where, according to Keele, they include 70 

 impure limestones, argillites, and quartzites, with Pseudomonotis siibcir- 

 cularis, "Halobia lommeli" and Arpadites (?). 



The generally accepted assignment of the Pseudomonotis-bearing beds 

 of Alaska to the horizon of the Upper jSToric of Europe and Asia is based 

 on the close relationship of the Alaskan fossil identified as Pseudomonotis 

 subcircularis (Gabb) with Pseudomonotis oclioiica (Keyserling), which 

 is the characteristic fossil of the boreal Upper Noric beds of Asia. This 

 relationship was long ago shown by Teller 71 and by Mojsisovics. 72 Speci- 

 mens from Cold Bay, on the Alaska Peninsula, have more recently been 

 examined by Freeh, 73 who has identified them as including both the typi- 

 cal form of Pseudomonotis oclioiica (Keyserling) and also Pseudomonotis 

 ocliotica var. sparicoslata Teller. Further confirmation of this correla- 

 tion is found in the general similarity of the Alaskan Upper Triassic sec- 

 tion as a whole to that of California and other regions. 



63 J. F. Whiteaves : On some fossils from the Triassic rocks of British Columhia. Con- 

 tributions to Canadian paleontology, vol. 1, pt. ii, No. 3, pp. 127-132. 



ee George M. Dawson : Report on the area of the Kamloops map-sheet, British Colum- 

 bia. Geol. Survey of Canada, Ann. Kept, (new series), vol. ii, 1S96, pp. 50B-137B. 



07 J. F. Whiteaves : Notes on some Jurassic fossils collected by G. M. Dawson in the 

 Coast Range of British Columbia. Geol. Survey of Canada. Report of progress for 1S76- 

 1877, p. 158. 



08 Alfred R. G. Sehvyn : Report on exploration in British Columhia. Geol. Survey of 

 Canada. Report of progress for 1875-1876, pp. 75, 80, 07. 



68 R. G. McConnell : Report on an exploration of the Finlay and Omenica rivers. Geol. 

 Survey of Canada. Ann. Rept. for 1804, vol. vii (new series), 1896, pp. 32C, 35C. 



70 J. Keele : Report on the upper Stewart River region, Yukon. Geol. Survey of Can- 

 ada, Ann. Rept. (new series), vol. xvi, 1006. pp. 14C, 15C, 17C. 



71 Friedrick Teller : Die Pelecypod-Fauna von Werchojansk in Ostsiberien. Mem. Acad. 

 Imp. Sci., St. Petersburg, 7th ser., vol. 33, No. 6, 1886, pp. 110, 113, 115. . 



7 - Edmund von Mojsisovics : Arktische Triasfaunen. Mem. Acad. Imp. Sci., St. Peters- 

 burg, 7th ser., vol. 33, No. 6, 1886, p. 147. 



73 Fritz Freeh : Die zircumpacifische Trias. Lethsea geognostische, Teil ii, Bd. 1, 1908, 

 p. 489, pi. 68, fig. 3a. 



